The most effective way to get rid of string algae* is the use of Algae Control. When properly dosed, Algae Control is safe and can work wonders at ridding your pond of string algae! When dosing your pond with Algae Control, there are a few things that you’ll want to keep in mind.
First, Algae Control is essentially a weed killer. Because of this, it’s extremely important to know the size of your pond. For help in calculating how many gallons your pond has, see our Pond Volume Calculator. Overdosing can lead to harming your fish, or even have fatal results.
Second, decaying dead algae will consume oxygen. Be sure that your pond has plenty of oxygen by keeping all waterfalls going, and air stones if you have them. Check out our aeration bundles to help keep your pond well oxygenated. You will want to remove as much algae by hand to lessen the consumption of oxygen once the algae begins to die off.
Use 2.5oz of algae control per 1,000 gallons. For example, if you have a 10,000 gallon pond, one treatment would be 25oz. A single, one gallon container would last about 5 full treatments.
If your string algae problem is particularly bad, treat your pond with one full dose, followed by a second full dose one week later. Usually two treatments will rid the pond of string algae. Then consider dosing your pond every two weeks with half the normal dose, as a maintenance dose. Algae Control can be stressful to koi, so please do not dose more than once per week.
* String algae is the common term for filamentous algae. String algae often clumps and tangles together to form thick blanket like mats.